“…Densities and associated molar masses were previously measured for asphaltenes from dif-Ž ferent sources and for different extraction methods Yarranton and Masliyah, 1996;Yarranton et al, 2000;Akbarzadeh . et al, 2001;Alboudwarej et al, 2002 . The molar masses were measured with VPO at 50ЊC in toluene, but the density measurements were made at 23ЊC.…”